linera-io/linera-protocol · error · anyhow

Invalid blob ID

Error message

Invalid blob ID: {s}

What it means

BlobId::from_str expects exactly '<BlobType>:<CryptoHash>' (e.g. 'Data:6ab0f8e8...'). The string is split on ':' and must produce exactly 2 parts; any other part count raises this error. If the count is 2 but the type or hash is malformed, you instead get the chained 'Invalid BlobType!' or 'Invalid hash!' context errors, so this specific message means the overall shape is wrong.

Solutions

1. Use the exact Display form: format!("{}:{}", blob_type, crypto_hash)
2. Round-trip through BlobId::to_string() instead of building strings by hand
3. If your source data uses a different separator (e.g. '/'), convert it by splitting once on that separator and re-joining with ':'

Example fix

// before: bare hash has no 'type:' prefix
let blob_id: BlobId = hash_str.parse()?; // Err: Invalid blob ID: 6ab0f8e8...

// after: type-prefixed Display form
let blob_id: BlobId = format!("Data:{hash_str}").parse()?;

fn looks_like_blob_id(s: &str) -> bool {
    let Some((ty, hash)) = s.split_once(':') else { return false };
    !ty.is_empty()
        && hash.len() == 64
        && hash.bytes().all(|b| b.is_ascii_hexdigit())
}

fn parse_blob_id(s: &str) -> Option<BlobId> {
    s.parse().ok()
}

When it happens

Trigger: Calling \"...\".parse::<BlobId>() on a string with zero colons or two-or-more colons: a bare hash like '6ab0f8e8...', a type alone like 'Data', or a string where the hash portion itself contains ':' separators.

Common situations: Hand-assembling blob IDs in glue code or shell scripts; passing a blob URL or a 'type/hash' string produced by another tool; copy-paste truncation from CLI output; passing a serialized JSON object where the Display string is expected.

Understand the failure class

Background: "invalid id" errors: invalid identifier format — why libraries reject IDs before lookup, and how to fix them — this error's family across 37 libraries.

Related errors

• Invalid parsing of GenericApplicationId
• Invalid stream ID
• Invalid address value
• failed to load data blob bytes from
• Failed to obtain a port

AI-assisted analysis of linera-io/linera-protocol@6c226ddcb3 (2026-08-22). Data as JSON: /api/errors/f4f393970407c922. Report an issue: GitHub.

Appendix: source

Thrown at linera-base/src/identifiers.rs:352

    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "{}:{}", self.blob_type, self.hash)?;
        Ok(())
    }
}

impl std::str::FromStr for BlobId {
    type Err = anyhow::Error;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        let parts = s.split(':').collect::<Vec<_>>();
        if parts.len() == 2 {
            let blob_type = BlobType::from_str(parts[0]).context("Invalid BlobType!")?;
            Ok(BlobId {
                hash: CryptoHash::from_str(parts[1]).context("Invalid hash!")?,
                blob_type,
            })
        } else {
            Err(anyhow!("Invalid blob ID: {s}"))
        }
    }
}

#[derive(Serialize, Deserialize)]
#[serde(rename = "BlobId")]
struct BlobIdHelper {
    hash: CryptoHash,
    blob_type: BlobType,
}

impl Serialize for BlobId {
    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
    where
        S: Serializer,
    {
        if serializer.is_human_readable() {
            serializer.serialize_str(&self.to_string())

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